Inertia catch for a vehicle latch

ABSTRACT

A latch mechanism for selectively latching a door to an automotive vehicle. The latch mechanism includes a latch hook movable between locked and unlocked positions relative to a striker bar fixedly secured to the vehicle. A release lever is operatively coupled between the latch hook and the latch mechanism for selectively actuating the latch hook between the locked and unlocked positions. An inertia lever is engagable with the release lever to prevent movement of the latch hook between the unlocked and locked positions. The inertia lever is movably coupled to the latch mechanism for movement in and out of engagement with the release lever in response to a threshold acceleration of the vehicle. A slot is formed in the release lever presenting sides engagable with the inertia lever to automatically rock the inertia lever in response to movement of the release lever to prevent seizing of the inertia lever within the latch mechanism due to lack of use.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a latch for selectively locking a door of anautomotive vehicle, and more particularly, a lateral inertia lever forpreventing the release of the latch in the event of a lateral vehicleimpact.

2. Description of the Prior Art

Automotive vehicles include hinged doors for allowing and closing accessto passenger or cargo compartments within the vehicle. Typically, alatch mechanism is coupled between the door and the vehicle forreleasably locking the door in a closed position with the vehicle. Arelease mechanism is typically coupled to the latch mechanism forselectively locking and unlocking the latch mechanism. It remainsdesirable to provide a mechanism for preventing the latch mechanism fromunlocking during a side impact upon the vehicle.

SUMMARY OF THE INVENTION

According to one aspect of the invention, a latch mechanism is providedfor selectively latching a door to an automotive vehicle. The latchmechanism includes a latch hook movable between locked and unlockedpositions. A release lever is operatively coupled to the latch hook forselectively moving the latch hook between the locked and unlockedpositions. The latch mechanism includes an inertia lever engagable withthe release lever to prevent movement of the latch hook between thelocked and unlocked positions. The inertia lever is movably supportedwithin the latch mechanism for moving in and out of engagement with therelease lever in response to a side impact upon the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the present invention will be readily appreciated as thesame becomes better understood by reference to the following detaileddescription when considered in connection with the accompanying drawingswherein:

FIG. 1 is a partial perspective view of an automotive vehicleincorporating a latch mechanism according to one embodiment of theinvention;

FIG. 2 is a partially exploded perspective view of the latch mechanism;

FIG. 2 a is a perspective view of a release lever in the latchmechanism; and

FIG. 3 is a perspective view of the latch mechanism.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the figures, FIG. 1 illustrates a door 10 for an automotivevehicle 12 incorporating a latch 20 mechanism according to oneembodiment of the invention. The door 10 is hinged to the vehicle 12 forpivotal movement between a closed position nested within an opening 14in the vehicle and an opened position to allow access into the vehicle12 through the opening 14. The latch mechanism 20 is fixedly mounted tothe door 10 for releasably locking the door 10 in the closed position.

Referring to FIGS. 1-3, the latch mechanism 20 includes a housing 19having a first side 21 and an opposite second side 23. A latch hook 22is disposed on the first side 21 of the housing 19 and is lockablyengagable with a striker bar 24 fixedly secured to the vehicle 12. Thelatch hook 22 is movable between a locked position lockingly engagedwith the striker bar 24 and an unlocked position disengaged with thestriker bar 24 to allow movement of the door 12 between the closed andopened positions. The latch hook 22 is biased toward the locked positionby a biasing member (not shown) of any suitable variety, such as a clockspring extending between the latch mechanism 20 and the latch hook 22. Arelease lever 30 is pivotally mounted to a mounting bracket 31 that isdisposed on the second side 23 of the housing 19 and is operativelycoupled to the latch hook 22 for moving the latch hook 22 between thelocked and unlocked positions in response to clockwise andcounterclockwise movement of the release lever 30, as viewed in FIGS. 2and 3. A detailed description of the structure and function of such alatch mechanism 20 is disclosed in commonly owned U.S. Pat. No.6,328,353 B1 issued on Dec. 11, 2001, which is incorporated herein byreference in its entirety.

The release lever 30 includes a proximal end 32 pivotally coupled to themounting bracket 31 by a pivot pin 33 and an opposite distal end 34extending outwardly from the latch mechanism 20. The release lever 30includes opposite upper and lower edges 36, 38 extending longitudinallybetween the proximal and distal ends 32, 34. A raised abutment surface40 is formed along a portion of the lower edge 38 adjacent the distalend 34. A relief slot 42 is cut or formed in the lower edge 38 betweenthe proximal end 32 and the abutment surface 40. The slot 42 extendsbetween opposing first and second sides 44, 46. The first side 44 of theslot 42 and the lower edge 38 intersect to present a generally raisedabutment tip 48.

The latch mechanism 20 includes an inertia lever 50 extending betweenopposite proximal and distal ends 52, 54. The distal end 54 is definedby a bent tab 58 engagable with either the abutment surface 40 or theslot 42 in the release lever 30. The proximal end 52 of the inertialever 50 is pivotally coupled to the mounting bracket 31 by a pivot pin56 for moving the tab 58 between engagement with the abutment surface 40or the slot 42. A biasing member 60 extends between the inertia lever 50and the housing 19 for biasing the inertia lever 50 in acounterclockwise direction, as viewed in the figures, towards engagementwith a stop 62 formed in the mounting bracket 31. With the inertia lever50 abutting the stop 62, the tab 58 is presented for moving in and outof the slot 42 to allow counterclockwise and clockwise movement of therelease lever 30 about the pivot pin 33 for actuating the latch hook 22between the unlocked and locked positions, respectively. The first side44 of the slot 42 and the tip 48 engage the tab 58 to lightly toggle theinertia lever 50 in and out of contact with the stop 62 during clockwiseand counterclockwise rotation of the release lever 30.

A weight 70 is fixedly secured to the inertia lever 50 between theproximal and distal ends 52, 54 by any suitable means, such as weldingor bolting. The weight 70 has a predetermined mass and is secured to theinertia lever 50 at a predetermined distance from the pivot pin 56 tocause clockwise rotation of the inertia lever 50 against the bias of thebiasing member 60 beyond a threshold lateral acceleration of the vehiclegenerally associated with a side impact upon the vehicle.

In operation, under normal vehicle operating conditions, the releaselever 30 is rotated counterclockwise and clockwise for actuating thelatch hook 22 between the unlocked and locked positions, respectively.The biasing member 60 continuously biases the inertia lever 50 againstthe stop 62. As a result of this bias, the release lever 30 is permittedto rotate counterclockwise to unlock the latch hook 22 because the slot42 is generally aligned with the tab 58 enabling the tab 58 to enter theslot 42. In addition, the arcuate movement of the release lever 30,causes the first side 44 of slot 42 and the tip 48 to engage the tab 58to rock the inertia lever 50 in and slightly out of contact with thestop 62 during clockwise and counterclockwise rotation of the releaselever 30 to prevent the inertia lever 50 from binding on the pivot pin56.

In the event of a side impact of the vehicle 12 or similar suddenacceleration, the weight 70 applies a torque moment upon the inertialever 50 to cause the inertia lever 50 to rotate clockwise so that thetab 58 is presented for engaging the abutment surface 40. Should therelease lever 30 rotate counterclockwise, the abutment surface 40 willengage the tab 58. While engaged with the abutment surface 40, the tab58 prevents actuation of the latch hook 22 to the unlocked position bypreventing counterclockwise movement of the release lever 30.

The invention has been described in an illustrative manner, and it is tobe understood that the terminology, which has been used, is intended tobe in the nature of words of description rather than of limitation.

Many modifications and variations of the present invention are possiblein light of the above teachings. It is, therefore, to be understood thatwithin the scope of the appended claims, the invention may be practicedother than as specifically described.

1. A latch mechanism for selectively latching a door to an automotivevehicle, said latch mechanism comprising: a latch hook movable between alocked position and an unlocked position; a release lever operativelycoupled to said latch hook for selectively moving said latch hook fromsaid locked to said unlocked position; and an inertia lever movablysupported within said latch mechanism and biased to a first position;wherein said release lever includes a slot and in a normal operatingcondition said inertia lever is aligned with said slot to allowactuation of said release lever, said release lever slot presentingsides for engaging a portion of said inertia lever for automaticallytoggling said inertia lever away from said first position in response tomovement of said release lever to prevent seizing of said inertia leverwithin the latch mechanism; and wherein said inertia lever includes acounterweight portion for moving said inertia lever out of alignmentwith said slot and into blocking engagement with said release lever inresponse to a side impact upon the vehicle in order to prevent actuationof said release lever and thereby inhibit movement of said latch hookfrom said locked position into said unlocked position.
 2. A latchmechanism according to claim 1, wherein said inertia lever includes atab and said slot of said release lever is aligned with and engages saidtab when said release lever is actuated to unlock said latch hook whensaid inertia lever is in said first position.
 3. A latch mechanismaccording to claim 2, wherein upon side impact said inertia lever movesto said blocking engagement position such that said tab is not alignedwith said slot.
 4. A latch mechanism according to claim 3, wherein saidinertia lever is pivotally mounted within said latch mechanism.
 5. Alatch mechanism for selectively latching a door to an automotivevehicle, said latch mechanism comprising: a housing including a firstside and an opposite second side; a latch hook disposed on said firstside of said housing and moveable between a locked position and anunlocked position; a release lever disposed on said second side of saidhousing and operatively coupled to said latch hook for selectivelymoving said latch hook from said locked to said unlocked position; andan inertia lever movably supported on said second side of said housingand biased via a spring to a first position; wherein said release leverincludes a slot and in a normal operating condition said inertia leveris aligned with said slot to allow actuation of said release lever, saidrelease lever slot presenting sides for engaging a portion of saidinertia lever for automatically toggling said inertia lever away fromsaid first position in response to movement of said release lever toprevent seizing of said inertia lever within the latch mechanism; andwherein said inertia lever includes a counterweight portion for movingsaid inertia lever into a second position out of alignment with saidslot in response to a side impact upon the vehicle in order to preventactuation of said release lever and thereby inhibit movement of saidlatch hook from said locked position into said unlocked position.
 6. Alatch mechanism for selectively latching a door to an automotivevehicle, said latch mechanism comprising: a latch hook moveable betweena locked position and an unlocked position; a release lever operativelycoupled to said latch hook for selectively moving said latch hook fromsaid locked to said unlocked position; an inertia lever including acounterweight portion movably supported within said latch mechanism forblocking movement of said release lever in response to a side impactupon the vehicle; means for biasing said inertia lever to a firstposition; wherein said release lever includes a slot presenting sidesfor engaging a portion of said inertia lever for automatically togglingsaid inertia lever in response to movement of said release lever toprevent seizing of said inertia lever within the latch mechanism;wherein said inertia lever includes a tab and said slot of said releaselever is aligned with and engages said tab when said release lever isactuated to unlock said latch hook when said inertia lever is in saidfirst position; wherein upon said side impact said inertia lever movesto a second position such that said tab is not aligned with said slot tothereby block movement of said release lever.
 7. A latch mechanismaccording to claim 6, wherein said inertia lever is pivotally mountedwithin the latch mechanism and said release lever is pivotally mountedwithin the latch mechanism.
 8. A latch mechanism according to claim 4,wherein said release lever is pivotally mounted within the latchmechanism.